Adjustable door switch



y 7, 1966 R. w. FRASER 3,251,971

ADJUSTABLE DOOR SWITCH Filed April 6. 1964 1311292120212" 1202182: W Fraser,

Jazzy.

United States Patent 3,251,971 ADJUSTABLE DOOR SWITCH Robert W. Fraser, Framingham, Mass., assignor to United-Carr Incorporated, a corporation of Delaware Filed Apr. 6, 1964, Ser. No. 357,639 Claims. (Cl. 200-159) This invention relates generally to switches and more specifically to switches having an adjustment feature for taking up variations in the supporting structures.

Frequently there is a comparatively great variation in distances between doors and jambs in articles of manufacture, such as refrigerators or motor vehicles. If a switch is mounted on either of the two mentioned elements there will, utilizing most presently known switches, be a malfunction if the distance between them is too great. Although the problem could be solved by making a very long switch, this is inefficient because of increased cost. The long switch is also inefl'icient because the plunger is likely to break after repeated operation and because there is a limit to the space available in most of the devices.

Through the use of the switch design disclosed hereinafter the take-up feature will prevent most of the disadvantages mentioned.

An object of the present invention is to provide an adaptor for a switch having means of adjusting a plunger associated with it for variations in the distance between a supporting structure and another.

A further object of the present invention is to provide an adjustable engagement between a tubular plunger and a series of teeth formed on an adaptor.

Other objects of the invention will, in part, be obvious and will, in part, appear hereinafter.

In the drawings:

FIG. 1 is a top plan view of the switch;

FIG. 2 is a bottom plan view of the switch;

FIG. 3 is a section taken on line 3-3 of FIG. 1;

FIG. 4 is a side elevation of the switch shown in FIG. 1; and a FIG. 5 is a section of a variation of the adaptor shown in FIG. 3.

There is shown in the drawing a switch comprising a metallic casing 10, an adaptor 12 formed of a plastic material, a contact assembly 14, a tubular plunger 16 open at one end and a helical compression spring 18.

The switch casing includes a body portion 20 generally tubular in configuration and open at both ends. An anular flange 22 is formed adjacent one open end of the casing 10 as shown in FIGS. 3 and 4. The annular flange 22 may be provided by a separate cap which is engaged to the body of the casing if desired. The flange 22 is in integral right angle relation with the body portion 20. The body portion 20 has a series of rectangular spring members 24- sheared from the body portion 20 and separated therefrom on three sides. The free terminal end of each spring member 24 is directed toward the flange 22, and each of the spring members 24 is spaced from the other. The spring members 24 are spaced in an annular configuration around the axis of the body portion and each has a slight knuckle formed between its terminal end and its connection with the body portion 20, as shown in FIGS. 3 and 4. The open end of the casing 10, remote from the flange 22, is constricted to provide a smaller diameter than the other opening. This constriction is provided by an angular circumferential shoulder 26 which is directed toward tween the terminal ends thereof. The separator 28 divides the adaptor 12 into an upper portion 30 and a lower portion 32. The upper portion 30 is provided with a series of circumferential annular teeth 34 which are spaced from each other axially-in a steplike relationship. The lower portion 32 has its free terminal end in the form of an arrowhead and has a circumferential groove 36 spaced from the tip of the terminal end as shown in FIG. 3.

The contact assembly 14 comprises a tubular, receptacle portion 38, open at both ends, and a cup-shaped contact portion having a base portion 42 extended to integrally engage the bottom of the receptacle portion 38 as shown in FIG. 3. An aperture 44 is formed in the base portion 42 and is defined by a series of rectangular teeth. Each of the teeth 46 is spaced from the others. The upstanding wall (not numbered) which extends from the base portion 42 does not describe a complete circle but rather a circle which is interrupted at its connection with the receptacle portion.

The switch is assembled by first placing the spring 18 into circumscribing relation with the lower portion 32 of the adaptor 12. The spring 18 and the adaptor 12 are then passed into the casing 10 from the open end adjacent the flange 22 until one end of the spring 18 abuts a portion of the inner surface of the shoulder 26 of the casing 10 and the other end of the spring 18 abuts the surface of the separator 28 of the adaptor 12 as shown in FIG. 3. The groove 36 of the adaptor 12 is passed through and lies beyond the constricted end of the casing 10. The terminal end of the upper portion 30 can now be held and axial pressure applied to push the arrowhead of the adaptor between the teeth 46 of the contact assembly 14 until the teeth 46 engage against the inner wall of the groove 36 as shown in FIG. 3.

The circle described by the free ends of the teeth 46 is of less diameter than the circle described by the outer edge of the walls forming the groove 36 but of only slightly less diameter than the root of the groove 36. The upper edge of the contact portion abuts the outer surface of the shoulder 26, when the adaptor is in a rest position. The crests of the teeth 34 of the adaptor 12 define a diameter slightly greater than the internal diameter of the core 48 of the plunger 16. The external diameter of the plunger 16 is less than that of the opening of the casing 10 adjacent the flange 22. Initial assembly of the plunger 16 with the adaptor 12 is accomplished by pressing the plunger 16 onto the adaptor 12 so that a few of the teeth 34 of the adaptor 12 engage the internal wall of the core 48 of the plunger 16 as shown in FIG. 3. A comparatively large distance remains, at this stage, between the inner surface of the cap portion 50, which closes one end of the plunger 16 and the free end of the upper portion 30 of the adaptor 12.

The switch assembly is engaged in an apertured support, such as the door jamb (not shown) of a refrigerator or automobile, by passing the body portion 20 of.

the casing 10 into an aperture formed in the door jamb until the flange 22 rests against the outer surface of the jamb and the spring members 24 engage either the wall of the aperture or the under surface adjacent the aperture.

Adjustment of the switch is accomplished by slamming the door against the plunger 16. The door will force the plunger 16 and the adaptor 12 against the spring .18 thus disengaging the contact assembly 14 and the shoulder 26. This disengagement will continue until'the spring is sufficiently compressed to apply a resisting force which would then cause the plunger 16 to pass over the teeth 34. This movement of the plunger in relation to the adaptor will continue until the door no longer exerts a strong compressing force. This adjustment will take 3 place over a wide range of distances which may exist between the jamb and the door. Of course, when pressure is removed from the plunger 16, such as occurs when the door is opened, the spring 18 will, through the adaptor 12, pull the contact assembly 14 into engagement with the shoulder 2-6 thereby making electrical contact and actuating the electrical circuit involved.

In FIG. of the drawing there is shown a variation of the adaptor disclosed in FIGS. 1 through 4 and is, in most respects, similar to the original adaptor 12 except that the upper portion 30a has a core 52 formed therein. The advantage of having a core 5-2 formed in the upper portion 30a is that it allows an inward flexing of the upper portion when it is engaged with the plunger.

While there has been illustrated and described one preferred embodiment of the invention, it should be understood that the invention is best defined by the following claims.

I claim:

1. A switch comprising a switch casing, an adaptor mounted in said casing, said adaptor having two terminal ends and having a shoulder element extending therefrom between said terminal ends, dividing said adaptor into an upper portion and a lower portion, said upper portion having a series of teeth extending therefrom, a plunger, having a portion thereof, in movable engaged relation with said upper portion and a compression spring circumscribing a portion of said lower portion and being sandwiched between said shoulder element and a portion of said switch body and a contact means capable of being actuated by said adaptor.

2. A switch comprising a switch casing and adaptor associated with said casing, said adaptor having a shoulder element extending therefirom dividing said adaptor into an upper portion and a lower portion, said upper portion having a series of teeth extending therefrom, a plunger, having a portion thereof, in movable engaged relation with said upper portion, and spring means sandwiched between said shoulder element and upper portion having a series of teeth extending therefrom, a plunger having a portion thereof in movable engaged relation with said upper portion and a compression spring circumsbribing a portion of said lower portion being sandwiched between said flange and said internal shoulder, and a contact means capable of actuation by said adaptor.

4. A switch as set forth in claim 3 wherein said adaptor is engaged with said contact means outside the area defined by said housing.

5. A switch as set forth in claim 4 wherein said plunger is in the form of a tube closed at one end providing a core and said teeth of said upper portion are engaged against the wall of said core.

KATHLEEN H. CLAF-FY, Primary Examiner.

BERNARD A. GILHEANY, Examiner. D. SMITH, Assistant Examiner. 

1. A SWITCH COMPRISING A SWITCH CASING, AN ADAPTOR MOUNTED IN SAID CASING, SAID ADAPTOR HAVING TWO TERMINAL ENDS AND HAVING A SHOULDER ELEMENT EXTENDING THEREFROM BETWEEN SAID TERMINAL ENDS, DIVIDING SAID ADAPTOR INTO AN UPPER PORTION AND A LOWER PORTION, SAID UPPER PORTION HAVING A SERIES OF TEETH EXTENDING THEREFROM, A PLUNGER, HAVING A PORTION THEREOF, IN MOVABLE ENGAGED RELATION WITH SAID UPPER PORTION AND A COMPRESSION SPRING CIRCUMSCRIBING A PORTION OF SAID LOWER PORTION AND BEING SANDWICHED BETWEEN SAID SHOULDER ELEMENT AND A PORTION OF SAID SWITCH BODY AND A CONTACT MEANS CAPABLE OF BEING ACTUATED BY SAID ADAPTOR. 